Ummm...hey.... well, I've just picked up a book titled "My Husband Betty" by Helen Boyd, published in 2003. Two things to consider:
1) I've not read it yet so I can't even give my personal take on it.
2) I'm not TG, so when I do read it I can't tell you how accurately it would describe/explain crossdressing.
But, here are some excerpts from the cover,
"Boyd explains the 'taxonomy' of the transgendered, the distinct societeis within the transgendered community, the effects of the closet, sexuality, and the issues faced by the wives and girlfriends of crossdressing men." "....My Husband Betty gives even treatment to both crossdressers and their spouses, with hard candor and tender insight and empathy. Some readers may bristle at comments that perhaps hit too painfully close to home. However, it's done in the same vein as a mother would chasten her rambunctious child, with a swift swat followed by a hug and reminder that she still loves and understands....."
--Vanessa Edwards Foster, Chair and Co-founder, National Transgender Advocacy CoalitionThere's also a website listed www.myhusbandbetty.com
In casual browsing through the book, it seems the author is all for trying to understand and support her husband, so it may be worth a look. Good luck !!